One vertex per element, one color per generator, with an edge from x to x·s.
(2,4)(13,14)(15,21)(16,20)(17,26)(18,22)(19,25)(23,27)(24,28) involution — undirected(5,6,8,9)(7,10,11,12)(13,15)(14,19)(16,25)(17,23)(18,24)(20,28)(21,26)(22,27)(1,2,3,4)(6,9)(7,11)(13,16,18,17)(14,20,22,26)(15,23,24,25)(19,21,27,28)(5,7)(6,10)(8,11)(9,12)(13,15)(14,21)(16,23)(17,25)(18,24)(19,26)(20,27)(22,28) involution — undirected(6,9)(7,11)(14,22)(15,24)(20,26)(23,25) involution — undirectedA Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.